import React, { Component } from 'react'
import PubSub from 'pubsub-js'
import './index.css'

export default class List extends Component {
  // 初始化状态
  state = {
    users: [],  // users初始值为数组
    isFirst: true, // 是否为第一次打开页面
    isLoading: false, // 标识是否处于加载中
    err: '' // 存储请求相关的错误信息
  }

  componentDidMount() {
    this.token = PubSub.subscribe('info', (_, data) => {
      this.setState(data)
    })
  }

  componentWillUnmount() {
    PubSub.unsubscribe(this.token)
  }

  render() {
    const {users, isFirst, isLoading, err} = this.state
    return (
      <div className="row">
        {
          isFirst ? <h2>Enter name to search</h2> :
          isLoading ? <h2>Loading...</h2> : 
          err ?  <h2 style={{color: 'red'}}>{err}</h2> : 
          users.map(userObj => {
            return (
              <div className="card" key={userObj.id}>
                <a href={userObj.html_url} target="_blank" rel="noreferrer">
                  <img src={userObj.avatar_url} alt="head_portrait" style={{width: '100px'}}/>
                </a>
                <p className="card-text">{userObj.login}</p>
              </div>
            )
          })
        }
      </div>
    )
  }
}
